谷氨酸螯合钙替代部分食盐对兔肉肌原纤维蛋白热凝胶和乳化特性的影响

为降低凝胶类低温肉制品中的钠离子含量，研究谷氨酸螯合钙替代部分食盐对兔肉肌原纤维蛋白加工特性的影响。从兔腰大肌中提取肌原纤维蛋白，添加质量分数为1.25%的谷氨酸螯合钙，再分别添加0.4%、0.8%、1.2%、1.6%、2.0%的食盐（食盐组成为70%NaCl和30%KCl），研究肌原纤维蛋白流变特性、保水性、乳化活性和乳化稳定性以及乳化体系复合热凝胶的保油保水性变化，并以3%食盐组作为对照。结果表明：食盐添加量增多，肌原纤维蛋白热凝胶储能模量（G’）增大，1.2%食盐组G’值高于对照组（P＜0.05）；但是凝胶保水性先增强后减弱，1.2%食盐组保水效果最好。食盐添加量增多，乳化活性增大；而乳化稳定性以0.8%和1.2%食盐组最高，与对照组差异不显著（P＞0.05）。1.2%和1.6%食盐组的保油保水性显著高于对照组（P＜0.05）。结论：添加谷氨酸螯合钙可以使兔肉肌原纤维蛋白形成具有良好黏弹性和保油保水性的低钠热凝胶，凝胶类低温肉制品的NaCl添加量可以减至0.84%。

Effect of Partially Substituting NaCl by Calcium Diglutamate on Heat-Induced Gelation and Emulsification Properties of Rabbit Myofibrillar Proteins

This study attempted to reduce the content of sodium ion in low-temperature gel-type meat products byinvestigating the effect of partial substitution of NaCl by calcium diglutamate on processing properties of rabbit myofibrillarproteins. Rheological properties and water-holding capacity (WHC) of heat-induced gels from myofibrillar proteins extractedfrom rabbit Pasoas major (PM) muscle with the addition of 1.25% calcium diglutamate and 0.4%, 0.8%, 1.2%, 1.6% or 2.0%salt (comprised of 70% NaCl and 30% KCl) as well as emulsification capacity, emulsion stability, and water- and oil-bindingcapacities of myofibrillar protein-lipid emulsion composite gels were measured and compared with those observed when 3%salt was added (control). The results showed that the storage modulus (G’) of heat-induced myofibrillar gels was increasedwith increasing salt concentration and showed a significantly higher level at a salt content of 1.2% than at 3% (P ＜ 0.05);however, the WHC was decreased after an initial increase and reached the best level when the amount of added salt was1.2%. In addition, the emulsification capacity of myofibrillar protein-lipid emulsion composite gels was positively dependentupon salt concentration, and the highest emulsion stability was achieved at 0.8% and 1.2% without significant difference ascompared with the control group (P ＞ 0.05). The 1.2% and 1.6% salt groups exhibited significantly increased water- andoil-binding capacities compared with the control group (P ＜ 0.05). In conclusion, low sodium conditions caused by addingcalcium diglutamate improves the viscoelasticity and water- and oil-binding capacities of rabbit myofibrillar proteins. Hence,the NaCl content of gel-type low-temperature meat products can be reduced to 0.84%.